1. Field of the Invention
The invention relates to a sports boot, and in particular relates to a ski boot capable of being connected to a ski movable along the ground.
2. Prior Art
Today, in many modern types of sports, such as, e.g., in alpine skiing, cross-country skiing, speed skating, inline skating etc., sports boots made of a stiff, resistant material are used which, in the toe and heel regions thereof, are provided with connecting pieces usually integrated in the sole of the boot, so that a stable and, in respect of the particular type of sports practiced, functional connection to the sports tool, such as, e.g., the ski, can be achieved by means of mechanical elements, such as, e.g., the ski binding.
As a rule, these boots consist of a shell embracing the foot, as well as a sole plate. These two units may either be produced in one piece, e.g. by injection molding from a synthetic material, or if made of several parts, they may be mechanically interconnected, e.g. by screwing, riveting, gluing or the like. In ski boots, the sole plate and the shell usually are built up symmetrically to each other with regard to their longitudinal axes. This means that the natural V-position of the healthy human foot in a comfortable, relaxed standing manner is forced into a parallel guide on the ski, resulting in a rotation in the knee joint when setting the ski on edge, and accordingly the direction of load in the bone axes, thigh-bone and shin-bone, will no longer extend exactly linearly, but rather via angularities, resulting in possible knee in-juries and fatigue symptoms, and also not optimally ensuring the performance of skiing.
FIG. 2 shows a conventional boot with symmetrical construction of the shell 1, wherein the axis of symmetry of the sole plate and the axis of symmetry SX of the ski 3 are congruent. It is clearly visible that the centre of gravity of the pad BS is located between the axis of symmetry SX of the ski 3 and the outer edge Ka of the ski 3.
This construction causes an undesired pressure on the outer edge.
To improve this problem, a boot construction has been proposed in EP 0 634 900 B1, in which the connecting line between the center of the heel and the center of the sole arch accommodating the big toe extends in parallel to the movement direction of the ski. In ski boot constructions of this type, however, the center of gravity of the pad, which is defined by the center of the axis of the pad, also comes to lie between the longitudinal axis of the ski and the outer edge of the ski as is generally the case in ski boots of symmetrical construction. By this, a counter-productive behavior to skiing is achieved, since due to this position of the center of gravity of the pad, an increased pressure is exerted on the outer edge of the ski, the former acting against the desired direction of movement of the ski.
From DE 41 38 801 A and DE 43 03 189 A, ski boots with a shell and a sole have become known, wherein the shell encloses an angle with the sole. In this case, the heel is located within the middle of the ski and the inner edge of the ski. In these known ski boots, particularly during alpine skiing, difficulties have occurred when initiating a turn with the skis, in particular if the bottom ski is set on edge via its inner edge, since the position of the center of gravity of the pad has not been taken into consideration. Since the nerve strands meet in the region of the pad, the center of gravity of the pad is of particular importance from biomechanical points of view for triggering movements, in particular for directing skis.